Transaction

[Error Code: 1101] cadence runtime error Execution failed:
  --> c8cb26bd4e53e145baf02854cfb72f9fcb6fe1bc7153acc9e024b6e5a1570c23:80:20
   |
80 |         let item <- self.listing.purchase(
   |                     ^

error: pre-condition failed: listing has already been purchased
   --> 4eb8a10cb9f87357.NFTStorefront:243:16